1. Field of the Invention
The present invention relates to an information processing apparatus including a data interface between a system and an application.
2. Description of the Related Art
FA equipment and OA equipment are often used in complex system environments, raising issues related to procedures and formats for exchanging data. It is therefore important to study a data flow before constructing a system. However, even if careful study is made prior to system construction, systems today face rapid environment changes after being installed and often require installation of devices with new data interfaces (I/Fs).
In view of the foregoing, Japanese Patent Application Laid-Open Publication No. 2005-251120 (Patent Document 1) discloses an FA equipment I/F integrating device capable of facilitating update of an I/F upon introduction of new FA equipment or upon software upgrade.
Information processing apparatuses used in such a system environment not only handle complex data but also employ complex procedures and formats for exchanging the data between programs after loading the data through a data I/F. Similarly, procedures and formats used by an image processing apparatus for exchanging loaded data between programs are becoming complex.
Image processing apparatuses today have multiple functions such as printer, copier, facsimile and scanner functions, and include a control unit, a display unit, a printing unit and a scanner unit integrated in a single casing. Such an image processing apparatus realizes printer, copier, facsimile and scanner functions through execution of corresponding function programs by a control unit.
These functions of the image processing apparatuses use various types of information such as, for example, user information. User information may include user specific data such as user name, authentication password, mail address for use by the scanner function of the image processing apparatus, and facsimile number for use by the facsimile function of the image processing apparatus (For a method of managing user information in an image processing apparatus, see Japanese Registered Patent No. 3715629, for example).
The image processing apparatuses acquire various types of data (such as user information) in different formats from information (data) storage locations present in the environment surrounding the image processing apparatuses according to respective data access methods. Examples of a storage location include a local database (DB) in the hard disk (HD) of the image processing apparatus, an SD card (Secure Digital memory card) as an external storage medium, and an LDAP (Lightweight Directory Access Protocol) server connected via a network (for an information processing apparatus using information acquired from an LDAP server, see Japanese Patent Application Laid-Open Publication NO. 2004-274486, for example).
As one method for facilitating data management upon adding a new function (i.e. upon installing a new application) or upon being connected to a new storage location, a data format and a data access procedure used in the image processing apparatus may be integrated into one module as a data conversion rule by using the technique disclosed in Patent Document 1. The data conversion rule defines conversion between a data structure of system acquisition data acquired by the image processing apparatus and a data structure of application usable data (e.g. user information) usable by various function applications.
This method, however, has the following problems.
For example, with reference to FIG. 1, the user information used in the image processing apparatus includes data items acquired from plural storage locations such as a local DB, an SD card and an LDAP server. This user information is generated by using data conversion modules each having a function for converting a data structure of the corresponding data item into a data structure usable by applications according to the data format and the data access method handled by the corresponding storage location and the data structure of the user information. However, if an application for an e-mail transmission function is removed from the image processing apparatus, the data structure of the user information is changed to exclude the e-mail address. With this change, the data structure of the user information becomes different from one that is known to data converters, resulting in an error when the data converters generate the user information.
This method is highly dependent on the data structure and therefore has the following disadvantage. If the data structure of the application usable data is changed due to installation or uninstallation of an application or the like, since it is not clear which part of the data conversion module is dependent on the data structure and which part is not (i.e., since the part dependent on the data structure and the part independent of the data structure are not clearly separated from each other), the data structure change affects a great part of the data conversion function (i.e. a data I/F function), requiring changes therein. The same applies to the case where the data structure of the system acquisition data is changed by the storage location. These factors make it troublesome to develop and introduce a new extension function that uses a new data structure.